Malawi's new president, Bingu wa Mutharika, has been sworn in amid a second day of clashes between security forces and opposition supporters over his disputed election victory. The unrest has killed at least one person and possibly several more, and there are allegations that police used live ammunition to suppress the demonstrations.

Several African heads of state were present for the swearing-in of Bingu wa Mutharika, who has become Malawi's third president. He was the anointed successor of Bakili Muluzi, who was constitutionally required to step down after two terms in office.

Unrest broke out Sunday in townships around Blantyre after the Malawi Electoral Commission declared Mr. Mutharika the winner. He took about 35 percent of the vote, while his two closest challengers won 27 percent and 26 percent. The violence continued as he took the oath of office.

The man who placed third in the official standings, Gwanda Chakuamba of the Mgwirizano Coalition, accuses the electoral commission of fraud and says he should have been declared the winner. His coalition says it intends to challenge the results in court.

The head of the University of Malawi political science department, Mustafa Kennedy Hussein, places part of the blame for the opposition anger on an electoral system that allows someone to win the presidency with 35 percent of the vote.

"I think it is something to do with the electoral system," he said. "Because we would be talking about a different scenario if it was proportional representation. But now the voting pattern is along the regional lines, and it is only people who get the majority, even if they beat others by one vote, they still have to be declared the winner."

International election observers have given the poll a mixed evaluation. They say that while voting day was peaceful, there were serious irregularities in voter registration and a heavy bias in the state media toward the ruling party, the United Democratic Front. The European Union also said the ruling party used state resources in its campaign, and that former President Muluzi handed out money at election rallies.

The head of the EU observer mission, Marieke Sanders, wants to set the record straight after remarks that the former president made during the swearing-in.

"The former president, I have to say, Muluzi, he said that we the international observers had declared the elections as free and fair," he said. "That is definitely not so, because it is too early to give any comments on that, so we will not, we have not done so yet. The final report, that will give the assessment if we think the elections are up to the international standards. Because that is why we are here, to see whether these elections in Malawi were conducted according to international standards."

Analysts say the opposition probably has little chance of overturning the election in court.

But economists worry that continued unrest and a disputed poll could hurt Malawi's already sagging economy and its standing with international lenders.

In his inauguration speech, Mr. Mutharika promised sweeping reforms in the economy, the government and the agricultural sector, to make Malawi, what he called, a hunger-free nation.